Dr. Murray, who investigators have been looking into whether he gave the pop star a lethal dose of the anesthetic profopol in the hours before his death, said in August in a YouTube video, "I have done all I could do. I told the truth and I have faith the truth will prevail."

In her new ABC interview, Janet said it's still hard to imagine that her brother is no longer here.

"It's been a tough year," she said. "You have your days where it's just really – it's hard to believe. And a day doesn't go by that I don't think about him."

Janet recalled the moment she heard Michael had been taken to the hospital on June 25.

"I was at my house in New York. You know, another day. Another morning. And I get a call … [my assistant] said, 'Your brother's been taken to the hospital. It's on CNN right now,'" Janet said during the interview. "I called everyone's. There's a line busy or — someone wasn't picking up. I spoke to mother. I spoke to Tito. I spoke to my nephew Austin. I spoke to my sister La Toya."

When Janet did not hear back from her family, she called again – only to find out the tragic news.

"I told them to call me when they got to the hospital. And I remember thinking nobody's calling me back, so I tried calling again, and that's how I found out that he was no longer… I couldn't believe it," she said.

Janet said news of her brother's death was almost impossible to believe.

"It just didn't ring true to me. It felt like a dream," she explained. "It's still so difficult for me to believe. It's, you know, you have to accept what is. But it's hard. You have to move on with your life. You have to accept what is and I understand that."

The 43-year-old singer said she looks back on the last time she saw her brother with fond memories.

"We had a lot of fun, laughing. …I was being silly, acting silly. And he was sitting in front of me and just cracking up, laughing at me," she recalled. "I was being loud. And he thought it was so funny. I was just being stupid, acting silly."